Dental drill.



no.' 683,695. v Patented ont. l', Ism.

L. nAlLLAn. l

DENTAL umu..

(Applictinn lnd .hun 24, 1901.)

(no Mahal.)

rn: Noam: vcrzns no.. Pnozmumo.. WASHINGTON. n. c.

Nrrnn STATES PATENT OFFICE.

LOUIS MAILLARD, OF GALT, CANADA.

DENTAL DRILL.

SPECIFICATION forming part of Letters Patent No. 683,696, dated October1, 1901.

Application filed J une 24, 1901. Serial No. 65,886. (No model.)

To all wtont t may concern:

Be it known that I, LOUIS MAILLARD, of the town of Galt, in the countyof Waterloo and Province of Ontario, Canada, have invented certain newand useful Improvements in Dental Drills; and I do hereby declare thatthe following is a full, clear, and exact description thereof, referencebeing had to the accompanying drawings, which form part of thisspecification.

My invention relates particularly to the form and arrangement of thecutting edges, and has for its object to form the cutting edgesirregular with alternate similarity and the lands of the alternatecutting edges serrated and in such a manner that they will betterfacilitate the removal of the tooth substance, While the liability tochoke and interfere with the cutting edges is amply provided for by theadditional amount of clearance permissible with this form andarrangement of the cutting edges. This particular form and arrangementof the cutting edges is applicable to many of the various forms ofdental drills, and to illustrate -my invention I have shown this form ofconstruction adapted to and arranged in the form of what is better knownas a lissure-bur.

To such ends the invention consists in the construction and combinationof parts particularly described and claimed, reference being had to theaccompanying drawings, forming part thereof, in which similar figures ofreference refer to like parts throughout..

Figure 1 is a View in elevation of the entire dental drill, showing theimproved head and the usual style of shank. Fig. 2 is an enlarged viewin elevation of the cuttinghead. Fig. 3 is a detail View, much enlarged,of a portion of one of the serrated cutting edges; and Fig. 4 is anenlarged viewin plan, showing the arrangement of the cutting edges onthe end.

The various parts of my improved dental drill consist of the usual shankl, the contracted portion 2, and the laterally-projecting portion orcylindrical cutting-head 3. The cutter-head 3 is provided with twocutting-surfaces, the periphery of the cylindrical portion forming oneand consisting of cutting edges formed, preferably, by spiral iluting,and the end forming the other and con-l sisting of cutting edges formedbycross-fluting. The cutting edges of the end are contiguous with thoseof the side, standing at right angles in this form of fissure-bur. Thecutting edges are spaced irregular with alternate similarity, those onthe periphery consisting of plain and serrated cutting edges 4; and 5,respectively, and arranged alternately and those on the end consistingof plain cutting edges 6 and 7, contiguous with the cutting edges 4 and5, respectively.

The irregular spacing of the cutting edges permits the fluting to becarried toa greater depth adjacent to the alternate lands of thecutting-head 3. This additional amount of clearance is provided for thecuttings of the serrated cutting edge 5, which removes by far thegreater quantity, acting as a break and more readily removing the toothsubstance, while the alternate plain cutting edges maintain the desiredsurface.

The teeth 8 of the serrated cutting edges 5 are sort of a hooked-shapedratchet formed at an angle with the cutting-face 9 and having a backwardinclination or rake, the object of which is to assist the drill inpenetrating the tooth substance.

It will be observed that the cutting edges 6 and 7 are arrangedalternate, as shown in Fig. t---that is, those contiguous with thecutting edges -namely, the cutting edges 7 meet in the center of the endcutting-surface, and those contiguous with the plain cutting edges L-namely, the cutting edges 6-join the aforesaid cutting edges 7 a shortdistance from the center. From the foregoing it is obvious that thecutting edges 7 are radial, while the alternate cutting edges 6 aretangential.

I wish it understood that I do not confine myself to any particularnumber of cutting end the cutting edges contiguous with the saidserrated cutting edges meeting at a point in the center, and the cuttingedges 'contiguous With the alternate cutting edges joining the aforesaidcutting edges'a short distance from the Center, for the purposehereinbefore set forth.

In Witness whereof I have hereunto set my hand in presence of twoWitnesses.

LOUIS MAILLARD.

Witnesses:

J. MARION MCNAUGHTON, T. M. GIRCRICE.

